Double center drive crankshaft



p 1936. w. F. GROENE' Re. 20,090

DOUBLE CENTER DRIVE CRANKSHA-FT LATHE 0 Original Filed Dec. 15, 1928 T Sheets-Sheet 1 INVENTOR.

ATTORNEYS Sept. 1, 1936.

Original Filed D 90. 15, 1928 a 2 a w m m 0 mm a. m 7 wilt. Q

Sept. 1, 1936. w. F. GROENE I DOUBLE CENTER DRIVE CRANKSHAFT LATHE Original Filed Dec. 15, 1920 '7 Sheets-Sheet s 'iNV NTOR.

ATTORNEYJ Sept. 1, 1935.

W. F. GROENE DQUBLE CENTER DRIVE CRANKSHAFT LATHE Original Filed Deb. 15, 1928 '7 Sheets-Sheet 4 V I v INVENTOR.

Maw

A TTORNEYS 'Sept. 1, 1936. w. F. GROENE DOUBLE CENTER DRIVE CRANKSHAFT LATHE Original Filed Dec. 15, 1928 7 Sheets-Sheet 5 I INVENTOR.

BY I

A TTORNEYS Sept. 1, 1936; w. F. GROENE DOUBLE CENTER DRIVE CRANKSHAFT LATHE Original Filed Dec. 15, L928 7 sheets-Sheet 6 I INIV/ENTOR.

' (444w rzlza ATTORNEY-Y 'Reieeuease e 1,, 1936 UNITED STATES f Re. 20,090

some novnnn CENTER muvn camsmr'r LATHE 'William F. Groene, Cincinnati, ohm; assignor to The R. K. Le Blond Machine Tool Company, Cincinnati, Ohio, a corporation of. Delaware Original No. 1,843,359, dated February 2, 1932,

Serial No. 326,352, December 15, 1928,. Application for reissue July 2, 1936,'Serial No. 88,698

This invention relates to a novel method and the machinery for turning, in one turning operation, the flange end, the stub end, and the line bearings of acrank-shaft, whether the crankshaft in question be a 4 a 6, or an 8throw crankshaft.

It also consists ofa novel arrangement of tools, and of methods for feeding these tools to and away from the work and in synchronization with 10 each other, both in approach, turning and retreat from the work. 7

There is also a novel arrangement of a pair of driving chucks at the center of the work," and l of a method for centering, positioning, clamping, l5 steadying and driving the work'with and in these chucks. I a

A still further arrangement is one whereby the center tool units are supported by the two driving chuck housings and whereby the feed of the tools in this center tool holder is obtained by a novel driving arrangement from another set of tool units.

It also'consists of a novel tool slide having a two-way feed. 1

There is also a loading and unloading arrangement having an ability to receive the-work, to carry the same into the chuck, toan exact position of placement, lowering to the operation position, a disengaging feature and a retreat during the turning operations.

There is also a .novel steady rest for holdin the work for torsional strains during the turning operations.

Each of these features will be fully'descrlbe in'the descriptions to follow and other new and novel features pointed out, the invention being set forth in the appended claims.

The system outlined provides the following possibilities for the turning of the various types of 40 crank-shafts now in use in the internal combustion engines of the present day.

It provides for the turning, in one operation,. of the flange end, including the flrst or No. 1- line bearing, the No. 2 or center line bearing, and

the stub end including the No. 3 line bearing, of

.a four-throw or seven bearing crank-shaft.

The system also lends itself to the turning of ten bearing or six-throw, crank-shafts, as well as thirteen-bearing or eight-throw crank-shafts In the instance of the first mentioned crankshaftthe seven-bearing--the turning of the flange and stub end is coincident with that of the. three-line bearings,'the No. 2 line or center bear ing being turned by a separate set of tools from those that operate on the flange and No. 1 bearing and the stub'end and the No. 3 bearing, there set which 'operate on the No. 2 or center line '5 bearing, and a. front and rear set which operate on the stub end and the No. 3 line bearing, all of which operate uponthe crank-shaft simultaneously to perform their turning operations.

' Upon a six-throw crank-shaft having but-three 10 main bearings, the problems of turning are the' same as the four-throw crank-shaft, the line bearings being in the same position as in a fourthrow shaft.

A ten-bearing or six-throw shaft having four 15 line bearings and six connecting rod bearings presents a; slightly, different proposition in that there is one more central bearing to consider. .The method then is to turn the the flange end and No. 1 bearing with one group of tools; turn the Nos. 2 and 3 center bearings with a second group of tools; and turn the stub end and the No. 4 bearing with a third group ofv tools. All of the groups of tools coming into action at the same time and completing, in one action, the turning of the flange and stub ends together with the four-line bearings.

In the drawings:-:-

Figure 1 is a front elevation with the tool holders left off the 'tool slides on .the stub and flange ends. p

Figure 2 is a plan of the lathe.

Figure 3 is a side view, partly in section, of one of the center drive chucks, viewed from the tailstock end of Figure 1. s

Figure 4 is a vertical transverse sectionof the center tool unit on lines A of Figures 1 and '2, the near side plates being left oil and the bolts and rivets shown in section.

Figure 51s a vertical transverse section of the bucks and center tool unit on lines 3" of Figures 2, 3, 4 and 6. p

Figure 6 is a fragmentary elevation of the right hand center drive unit, viewed-from the left side.

Figure 'I is a plan of the lower half of the clamping elements shown in Figure 6.

Figure 8 is @a vertical transverse section on lines 0" of Figures 1 and 2, of the flange end front and rear tool assembly.

Figure 9 is a front elevation, partly in section, of the front stub end tool slide.

Figure 10 is a vertical side elevation of the same.

Referring to Figures 1 and 2, the bed of a lathe is shown at l and has 'a headstock 2, of a well' lgnown type, having an adjustable center carried by its spindle. The tailstock 3 is of a known typeficarrying also the usual adjustable center. The'headstock carries a driving pulley l to which asource of power may be applied. A shaft 5, driven by the gearing within the head, furnishes driving power to a unit of the machine as will be described later.

The chucking mechanism A driving chuck frame 6, carrying a chuckof the rotary type is locatednear the center of the -lathe,'and this chuck will hereinafter be called the flange end chuck, since its function is to grip a web of the crank-shaft on the flange end side of the chuck. A similar chuck frame I carries what will be hereinafter called the stub end chuck, because it engages a web toward the stub end of the shaft, is mounted on the bed, fairly close to the chuck frame 6, the spacing being sufllcient to expose the'center bearing of a crank shaft to be turned. Caps 8, forming the upper half of each of the driving chuck frames 6 and I, are bolted fast to lower parts I I) of the respective frames which are secured to the bed, thus forming circular containers for the chucks. The respective chuck frame caps have on their front edge flanges 9 and 9a, and the lower halves Id of the chuck frames have on their rear edges webs 9b the utility of which will be described later. As each of the.

' flanges having their edges turned upward to form a seat lib. Bronze bearing rings l2, seated fixedly in the frames 8 and 9, form a continuous bearing for the ring gear I I. The lower frame part In has a cavity l3 therein forming an oil reservoir. In order to distribute the lubricant in the reservoir, the bronze rings are-provided with slots l4 at their lower parts, and a pair of spring mounted rollers IS in the oil reservoir have contact with the oil and the said gear bearing flanges through the slots I4, thus serving to lubricate the ring gear. A hardened steel positioning block I. is mounted in a seat carried by the ring gear web Ila, this block having a pair of seats 61, H. A bearing pin I8 is carried in a boss Ila on the retracting the clamping dog l9.. A second bearing pin 2| is carried in the ring gear web Ha which supports a clamping lever 22, having a bifurcated outer end 22a. A self-aligning disc 23 having a tapered seat is mounted in the clamping lever 22.

A slot 24 in the disc 23, and a pin 25 carried by the clamping lever and projecting into the slot in the disc 23, allow a limited circular travel of the disc. The clamping dog I! is grooved at I90 to retain a link '26 having a bearing at its lower end on the pin l8a which is located in the dog I! at a point below the bearing of the said clamping same, the differences lying in the inner halves of the two chucks which face each other.

I employ a stud 21 mounted in a boss 21a. in the web I In of the gear ring. A clamping member 2 8 (Fig. 6) is mounted on the stud 21 and has a forked rear end 28a and aslotted front end 23b.

(Fig. 7) A second clamping member 29 having a reduced rear portion adapted to fit within the forked portion of the clamping member 18, and having a bifurcated outer end 3| is also mounted on the stud 21. A link 30 mounted on a pin 30a in the lower edge of the clamping member 23, and lying in the slotted portion of the clamping member. 28b, has a long threaded upper end upon which is mounted a special long nut 32.

The two clamping members have at their central portion semi-circular discs 35 each having a tapered outer edge for a portion of the circumference and a v-shaped notch with a flat base, for the remaining portion of the circumference (Fig. 6). The tapered portion fits into like seats in the clamping members, thus retaining the discs in the clamping members, while permitting them to travel circumferentially, limited by a stop pin and slot'as shown, in the same manner as described with reference to the disc 23. Carried on the rear of the clamping members are ears adapted for engagement with springs 33 and 34. The spring 33, fastened to the clamping member 29, tends to hold it bpen and away from the work being inserted. The spring.3l, fastened to the clamping member 28, is so proportioned as to balance the weight'of the clamping member and its parts, and to prevent all but slight dropping from its normal position.

The mechanism just described forms a torsional strain resisting unit. The stud I'Lbeing flrmly mounted in the body of the chuck itself with the two clamping members carried by it. with their self-adjusting gripping discs, supplement the other work gripping devices which have been described to form a three-point drive for the work. The construction prevents beyond any possibility, the dislodgement of the work by the tools.

Referring to the left hand or flange end chuck,

I have provided a pair of spaced lugs, one of which the tools. ring gear, and serves to mount a clamping dog l3. 1 A spring 20 secured to thering gear is.used for In Figures 1, 2, 3, 4, and 5, more especially in Figures 1 and 5, is best shown the driving mechanism for the ring gears. The shaft 38 is coupled at 40 with the shaft 5 located in the headstock of the lathe. This shaft 39 is mounted in bearings can'ied by the chuck frames 6 and I and extends from the coupling on the end of the shaft 5 through both frames and to the far side of the chuck frame I. At a point opposite the ring gears are fastened driving pinions 4|. The shaft 5 being a source of power, the shaft '40 and the two pinions carried by it are driven and in turn drive the ring gears II, and the chucking parts of the ring gear structure, and these chucking parts will in turn, when properly adjusted to the work, cause the work to rotate at a suitable rate to beoperated on by the tools.

Loading operation The loading and unloading operations of the work require a nicety of handling to the end that the tools be not damaged and that the work, when it is lowered into the chuck members, he in its exact position of placement, so .that when vaand lower filler castings.

rious clamping. steadying, and final positioning devices of the chuck come into minimum of final adjustment.

Attention is called. to a patent issued to me on- January 29, 1929, bearing No. 1,700,721, in which patent there is disclosed a loading device for placing a crankshaft in a lathe, in the form of a pneumatic hoisting and lowering crane, and it is the type thereindisclosed that isused in the machine herein being described, with a few changes to suit the present lathe and chuck struc- The loading structure as a whole is indicated at 42, consisting of a frame carried on the lathe bed, a carriage mounted on the frame and free to travel longitudinally thereon, a pair of adjustable stops for the carriage, one at each end of the frame, an arm," for holding the work to be inserted in the chuck, and a pneumatic cylinder for raising and lowering the work. It is to be noted that the carrying arm 43 in the present case has a longer. reach to enable it to move in past the center of the two driving chucks and is equipped with a pa r of hooks 44 on its lower edge and extending laterally therefrom for holding the work for insertion into the chucks.

" Center tool unit I The center tool unit is shown in Figures 1', 2, s, 4, and 6, but especially in Figures 2, 4 and 5.

Referring first to the front tool slide, it will be noted that it is formed of two heavy plates 45 and 45 having a lower filler casting 41 and an upper filler casting 48 located between them. The plates 45 and 45, together withthe filler castings 41, 48, are assembled in one unit by means of screws 49, and when so assembled, form a tool supporting and guiding unit which I have indicated generally at 50. As the two filler castings do not fill the space vertically, a pocket is formed between them for the mounting of a tool carrying a bar.

The flanges 9 and 9d (Figs. 1 and 3) at the fmnt of the chuck frames and the web 817 at the rear of the two chuck frames have a series of bolt holes 52 therein, When the tool unit 50 and its rearcounterpart 5| are assembled, they are placed between the two chucking units fitting tightly into position anda series of bolts 53 'are inserted in the bolt holes 52, and upon tightening these bolts, the tool carrying units and the chuck frames are clamped into a rigid, single unit of great strength yet readily disassembled for repair or inspection.

Referring again to the tool slide 50, I have provid'ed a flat tool carrying bar 54'mounted in the space in the slide 50 formed between the upper This tool bar carries on its inner end a mounting 55, for holding a tool, this mounting being of a familiar design. A rack bar 56 is mounted in a slot in the lower edge of the tool bar 54, which slot has shoulders at the ends which support the ends 54a of the rack bar.

this rack having a loose fit endwise and capable of being adjusted and locked in adjusted position by adjusting screws 51, 58, the former being an abutment screw. Hie adjusting ofthis rack makes possible close working limits for the tool with the'work as well as eliminating back lash.

The lower filler casting 41, has a pocket 59 in which is mounted a gear 5| on'a shaft 60', this gear having engagement with the rack 56 whereby, when the gear, is turned forward or reverse,-

the tool is fed, into or away from the work. The

play, there be a.

inner face.

'mounted in the bed of. the lathe.

. method of mounting and furnishing power to this shaft will be described below.

A taper gib 61, capable of being adjusted to take up wear, is mounted over the tool bar 54. Extensions 6! on the lower part of the side plate units 45, 46 (Figs. 1 2 and 3a carry bearings 64 in the outer extremities thereof. A bell crank lever 65, mounted on a shaft in the bearings 64,

'has its upper end pivoted to a link 86 pivotally mounted in a pocket on the rear of the tool bar, 54. A rod 61 is mounted on a pin extending between the lower edges of the side plates 45, 45, this rod, at its lower end, being threaded for a nut and washer and having a spring 68 mounted upon it. The lower end of the bell crank has a bearing upon the spring, the rod passing through a hole in the end of the lever. By adjusting the detailed description.

. Tool slides in flange end of lathe The flange end tool slides are shown in Figures 1, 2 and 8, but particularly-in Figure 8. The tool slide supporting bases are shown at 69 and III the usual V's II for the tool slides 12. The tool slides carry the tool holders 13. A downwardly extending guide I4 is securely bolted to the outward end of each of the, supporting bases 69 and 10, which guide has a groove in the inner face thereof. A rack bar 16 is mounted in each slot, which bar has teeth for a part of its length on its Racks ll are mounted on the bottoms of the tool slides 12, and are driven by the shafts Bil, heretofore referred to. These shafts are mounted in bearings in the supporting bases 59 and II, and extend through the bases toward upward movement of'the rack piece 16 will cause a rotation of the gear 18 and shaft 60 in each case and the consequent feed of the tool slides through racks I'I.

On each side of the machine there is a slide I9 mounted rigidly on the lathe bed I, and having I Arack B0 is secured on the rear of each slide and is driven I by a pinion gear, not shown, by powerfrom the headstock gear assembly. Each slide I9 has mounted on its facea cam plate 8| carrying a cam or form bar 82. The plates are capable of being adjusted on the screw and slot mounting Mo, to regulate the timing of the cams, as' is usual. The slides I9 on each side of the machine move in unison when in operation. A roller 83 is mounted on the rack piece 16 and extends over the path of the cam and in contact therewith. A second roller 84 acts as a retractor for the rack piece and through itsagency, the tools also. A steadying block 85 is provided which travels in a slot as m the guide" and holds the end or the rack bar secure.

The two slides at the back of the lathe, one at unItp-lower halves, and I8 in-the tool slide bases, are fastenedtothis shaft, as. been stated,

travel in the supporting base and a second slide i2 is mounted for longitudinal travel inthe slide II, this second slide carrying the tools ll. There the flange end, and having the number I, and the one at-the stub end,- having the number 88, are to be-understood as being to all intents and purposes, substantially identical with the flange end frontslide to which the description, as given, has been confined. Therefore, no detail description of these two slides is believed tobeneeded.

Referring to the shaft ldcarrledin the base '0 and passing ,intoandthrou'gh thebases of the chuck frames, .as7has been: it is to be noted that the-two gears, .II, the center tool a dqthat any motion'iinpartedto-the rack .10 by the] 82 will be translated to both the m ize and m l es w the two un s t?" 1 r ormovementat center of theworkj and betweenthetwo chuck units, as has bee'n described. 'l'hus'it willbe seen that thecams I! control themovement 'of the two flange endtool slides and incomplete unison therewith, the two center tooi bars and their tools.

stub end front tool we In- 1, 2, 9 and 10, but more especially in Figures 9 and 10- is shown the stub end front tool slide, in which 89 is a tool slide supporting base mounted on the lathe bed I. 90 is a rack and roll-.

er arrangement for the tool feed, similar in all respects to the ones of'the other slides, except that the teeth of the rackbar are at one side in this construction, instead of the, rear edge, as inthe other tool feeding units. 820 is the cam bar for this slide. A slide ll is moimted fortransverse is a U-shaped opening 94 (Fig. 2) in the outward end of the slide 00, and an upward'extension I! on the, supporting base, this extension extending up through the U-shaped opening in slide ii. A roller 96 is mounted on this extension and engages in acam slot 01 on the underside of the extension 98 of the second tool slide 92.

A shaft II, mounted in the supporting base, has a gear I00 keyed thereon and in engagement with the rack bar, and 'alsoa second gear III which 'drives' the cross slide. To this end a shaft III! is mounted in the supporting base above the shaft II and carries a gear III! in mesh with the gear Iii. A rack I, mounted on the underside of the sec- 0nd or tool carrying slide 9 I meshes with the-gear I". This rack hasteeth of a width in excess of that of the gear I03, so asto permit the slideli and rack IN to travel toward-or away from the work without coming out of engagement withthe gear. The crank-shaft A, which constitutes the work in this instance (Figs. 1,*3, and 5). has on the web sections, at each end of the shaft, a. pair of lugs I". These lugs serve as positioning and clamping devices for the shaft,-and their utility will be set forth in the descriptionof the operation of the machine to follow.

Before the rough crank-shaft forging is placed in the machine to be operated upon, the lugs III are machined to present a definite distance from the center of the shaft to the bottom of the lugs. This makes possible the coordinating of all the devices of the machinejto the end that each and The operator places a crank-shaft-in the hook i of the crane, as shown inl igure 1. All the clamping devices and the tools being in tracted position, the crane is pushed endwise, the shaft enteringthe stub end chuck through the gap Ins (Fig,

3) in the ring gear web, passing the center tool bars and through a similar gap in the flange end chuck until the crane carriage comes against the stop I", on .the crane frame. At this position to rest on the seats I! in the chuck bodies. which locate. the crank-shaft with regard to its vertical and lrelationship to the clamps and tools and a'gainstthe stop 38 which controls the longitudinal position r the shaft..

The two centers, are ,now brought forward to enter the ends of the shaft-and locked'in the usualmanner. r

At this "point thecrane arm or hook is slightly lowered and swung to the rear to release it, and

then retracted from the two chucks, as set forth in the pending application heretofore mentioned. It is to be noted that the hook or crane arm reaches past the centerof the two chucks and into.

the farthest chuck from the point of entry. r

The clamping lever 22 in the stub end chuck is self ,on the and web portion of the crank-shaft, as

clearly shown in Figure 5, at-the same time the tightening of the nut on link 28 causes a strain inward on the upper end'of clamping dog I 9, which clamping elements are a duplicate of the stub end chucks. We now -flnd the crank-shaft 'm be clamped in-a rigid manner against movement in any direction, but lest there be torsional strains unresisted near the center of the work, the clamp ing device shown in Figure 8 is provided.

This clamping device is carried on a stud 2'6, lying in theinner wall of the stub end chuck, and the operator reaches inside of the stub end chuck and brings the-arms 2t and 28 together over onev is seated against one of the lugs'il5, the other one of the connecting rod pins next to the center bearing and by the "tightening of the nut' 32 on the take a perfect seat on the crankpin, and an ideal strain resisting combination of clamping devices is thus formed. 7 v

The toolsmay-now be set in action and the 5 turning of the shaft proceeded with.

The two slides carrying the tools, under the influence of their cams '2. start into the flange end, turning the flange and the number I bearing,

the two sets of tools attacking the flangeehd from both sides at the same time imtil finished.

The two tool carrying bars of the 'center group of tools receive their power from the same cam, 82,

as do the flange end tool slides, the rack bar I6 driving the shafts 00, carrying the two driving gears II and II of each unit. Thus the number I- or center line bearing of the crank-shaftis turned in step with the flange end and the number I bearing. V I

The rear tool slideunit at the stub end is the I I upper end of link III, the semi-circular discs 35 r to one of the shafts I, is. in this instance,onlyaslongas thewidthoftheslide.

The action of the front tool slide at the stub end isi'in'nished from the cam II on the front slide.

devices,saidmeansbeingsupportedbysaidsup- Thetools at thestartcf their travelto thework, are outwardly and away from the work and toward the tailstock end of the lathe, so that their transverse travel in toward the work as well as their longitudinal travel causes them to reach the work just as the roller 96 reaches the straight part of the cam ll. The transverse travel havingstoppedwiththetoolsinpositionto attack the work, thelongitudinal travel continua and thestuhend-isturnedasshowninlflgurez where the tools are shown at the end of their travel.

While this action of the front tool has been takingplacethereartoolisapproachingthe work and forms the shoulders, both sets of tools completing their work together in unison with the completion of the work on the shaft by the other tools. v I The turning of the shaft now being completed, the tools are retracted, the clamps the crane brought forward into the chuck,the crane hook engaged under the crankshaft, and it is raised from the turning position and then moved longitudinally to the right out of the chucks until free, when it is removed from the hook'and another placed ready to begin the, cycle again.

It will be apparent that equivalent mechanical devices can be substituted for those shown and described without departing from the spirit of my invention. It will further be apparent that with aseries of center line hearings in a special crankshaft. it will be readily possible to space the "chucks, widen the tool supports and enter 'tools between the chucks to engage all line hearings located between them. t

Having thus described my invention, what I claim as new'and desire to secure by'Letters Patent, is:- v

l. In'acrank-shaft lathe, comprising a bed, a pair of continuous, rotary, chucking devices cmstituting the sole drivingand stcadying devices for a shaft in said lathe and supports therefor, on said bed located centrally of the lathe and means for supporting a toolbetween the said. chucking, driving and devices so as to engage a piece of work held in the chucking ports of the chucking, driving and 2. In a crank-shaft lathe, comprising a bed, a pair of continuous, rotary,"chucking devices constituting the sole driving and devices for a shaft in said lathe and supports therefor, on said bed located centrally of the lathe,

and means for supporting a tool from opposite sides of the lathe between the said chucking, driving and steadying devices so as to' engage a piece r work held in the chucking devices, said means being supported by said supports of the chucking, driving and steadying devices.

3. In a crank-shaft lathe, a pair of rotary chucking devices located centrally of the lathe,

and means for supporting a tool between the said chucking'devices so as to engage a piece of work held in the chucking devices, fixed frames for said rotary chucking devices, said tool supporting means being bolted together with said frame.

4.'-In a crank-shaft lathe, a pair of rotary chucking devices located centrally of the lathe, and means for supporting a tool from opposite sides of the lathe between the said chucking devices so as to engage from opposite sides a piece of work held in the chucking devices, fixed frames for .said rotary chucking devices, said tool supporting means being bolted together with said frame.

5. In a crank-shaft lathe, a pair of rotary chucking devices located centrally oi the lathe, and means for supporting a toolbetween the said chucking-devices so as to engage a piece of work held in the chucking devices, centers in said lathe for engaging the work therein, and tool supporting devices located also between centers and the chucking devices. I

6, In a crank-shaft lathe, a pair of rotary chucking devices located centrally of the lathe, and means for supporting a tool from opposite sides of the lathe between the said chucking devices so as to engage from opposite sides a piece of work held in the chucking devices, centers in said lathe for engaging the work therein, and-tool supporting devices located front and back of the lathe and between the chucking devices and each of the centers, making in all six 'tool supporting devices. p

' 7. In a crank-shaft lathe, a pair of rotary chucking devices located centrally of the lathe, and means for supporting a tool between the said chucking devices so as to engage a piece of work held in the chucking devices, centers in said lathe for engaging the work therein, tool supporting devices located also between both centers and the chucking devices, and means operated from a of the lathe and between the chucking devices and each of the centers, making in all six tool supporting devices, and means operated from a common source for advancing and retracting all 'tools in said supporting devices simultaneously.

9. In a crank-shaft lathe means for supporting and revolving a crank-shaft to be tuned from a position between the ends of the shaft, and at a plurality of points along. the shaft, cutting tools, and means for feeding them so as to turnallofthelinebearingsofsaidcrankshaft at a single operation, someof the tools operating between the supporting and revolving devices,

and some outside of the said devices. I

10. In a crank-shaft lathe, means for supportchucking device comprising a ring gear, and.

- .therein and having a member in whichthe web "pensated position against the pin of said crank-shaft from opposite sides with relation to each line bearing.

11. In a crank-shaft lathe, a center drive chucking device comprising a frame, a ringgear held in said frame, a crank-shaft pin engaging means retained in said ring gear comprising a plurality of jaws, and means for securing them together, and crank-shaft web engaging means arranged to engage the said web at morethan,

two points. I

. 12,.In a crank-shaft lathe, a center drive crank-shaft pinengaging means supported in said ringgear and having a pluralityof jaws, ,means for bringing and holding them together ,over the said pin, said jawshaving rocking en-,

gaging'elementstherein arranged to take a comwhen the jaws are brought together.

13. In a crank-shaft lathe, a center drive chucking device comprising a ring germ-and;- crank-shaft web engaging means "supported,

therein and having a member in whichthe web is seated,-a member movable to engage the web I iabove said seat, a stop in connection with said seat, and means for forcing a prepared portion of the web against said stop when the movable member is brought intoengagement with the web.-

14. In a crank-shaft lathe, a center -drive chucking device comprising a ring gear, and crank-shaft web eng ng means supported is seated, a member movable to engage the web above said seat, a stop in connection with said seat, and means for forcing a prepared portion of the web against said step when the movable member is brought into engagement with the web, said movable member having means thereon to engage the web at a plurality of points.

15. In a crank-shaft lathe, a center drive chucking device comprising a ring gear, and crank-shaft web engaging means supported therein and having a member in which the web is seated, a member movable to engage the web above saidseat, a stop in connection with said seat, and means for forcing a prepared portion .of the web against said step when the movable member is brought into engagement with the web, said movable member having means thereon to engage the web at a plurality of points said means having a rocking movementin its mounting on said movable means.

18. In a lathe, a tool slide comprising a frame,

,a tool carrying bar mounted to slide in said frame, means for driving the bar; and means for exerting spring pressure between the bar and the frameat all positions of the bar in the frame, said means comprising a compounding bell crank lever linked to the bar, and pivotally secured to the frame, and spring means for acting on said lever.

1'1. In combination in a lathe, a bed, a'plurality of tool slides on .'sa id bed having tool carrying members movable to advance and retract tools from the work, jcam means foroperating one of the tool slides, having power transmission means thereof being connected by a shaft with between it andthe slide, andpower on means for the other slide operativelyconnected with the power transmission means first men- 1 tioned.

18. In combination ina lathe, a bed,a plurality of tool slides on said bed having tool carrying members movable to advance and retract tools from the work, a rack and pinion feed for one of the slides, means on the bed of the machineto operate the same, and rack and pinion means for operating the other tool slide, the pinion the pinion for theslideflrst mentioned.

19. In a crank-shaft lathe. a bed,means thereon to support and revolve a crank-shaft inter-- mediate its ends, tool feeding devices located and operable tofeed appropriate tools for turning the stub end and-also Itheflange end of said shaft,

and means for operating s'aidi'ool feeding devices simultaneously, and further tool feeding means also operated simultaneously with the devices first above mentioned for turning a pin.- rality of line bearings of said shaft.

20. In a crank-shaft lathe, a pair-of rotary chucking devices located centrally of the lathe,

' and means for supporting a tool between the said chucking devices so as to en a e a piece of work held in the chucking device's, fixedframes 'fo'r'said chucking devices, saidtool supporting being bolted with said frames, "and-meansfor charging a shaft endwise into said chucklngfdevices.

21. In a crank-shaitlathe, a bed, means thereon to support and revolve a crank-shaft intermediateits ends, tool feeding devices located and operable to feed appropriate tools for turning the stud end and also the flange end of said shaft,

also operated simultaneously with the devices first hereinabove mentioned for turning all of thelinebearingsofsaidshaft,saidmeansto support and revolve a crank-shaft intermediate its ends being suchas to expose all of the line bearingsthereof for turning. X

22. In a crank-shaft lathe, a bed, means thereon to support and revolve a crank-shaft interand means for operating said tool feeding devices I simultaneously, and further tool feeding means mediate its ends, tool feeding devices located and operable to feed appropriate tools for turning the stub endand also the flange end of said crank-shaft, andmeans for operating said tool feeding devices simultaneously, and further tool feeding means also operated simultaneously with the devicesflrst above mentioned for turning all of the line bearings of said crank-shaft, the said means for supporting and revolving said crankshaft intermediate its ends being-a center drive chuck with means thereon to engage a web of said crank-shaft for supporting and rotating it in suchawayasto expose all of the line bearings thereof for simultaneous turning.

23'. In a crank-shaft lathe, a bed, means there- J ontosupport and revolve a'crank-shaft intermediate its ends, tool feeding devices located and operable to feed appropriate tools for turning.

the stub end and also the flange and of said crank-shalt, and means for operating said tool feeding devicessimultaneously; and further tool feeding means also operated simultaneously with the devices first above mentioned for turning a plurality of the line bearings of said crank-shaft, the said means for supporting and; revolving said crank-shaft intermediate its ends being a center drive chuck having means thereon to engage a web of said crank-shaft by engagement with at least one pre machined, relatively small locating surface onsaid web,, the complete engagement of said chuck being conflned to portions of the crank-shaft other than the line bearings thereof.

24. In a crank-shaft lathe, a bed, means there- .on to support and revolve a crank-shaft intermediate its ends, tool feeding devices located and operable to feed appropriate toolsfor turning the stub end and also the flange end of said crankshaft, and means for operating said tool feeding devices simultaneously, and further tool feeding means also operated simultaneously with the devices first above mentioned for turning all of the line bearings of said crank-shaft, the said means for supporting and revolving the crankshaft intermediate its ends, comprising means to engage portions of said shaft other than any line bearing thereof and to expose all line bearings for simultaneous turning.

25. In a crank-shaft lathe, a bed, means there on to support and revolve a crank-shaft intermediate its ends, tool feeding devices located and operable to feed appropriate tools for turning.

the stub end and -also the flange anal of said 5 crank-shaft, and means for operating'said feeding devices simultaneously, and further tool feeding means also operated simultaneously with the devices first above mentioned for turninga]! of the line bearings of said crank-shaft, the said 10 means for supporting and revolving the crankshaft intermediate its ends comprising means'to engage portions 'of said shaft other than any line bearing ,therejqf, said portions including atleast one relatively smallipre machined locating face 'on a web of said shaftf'insuch a way as to expose ans-or the line bearings of said shaft for simultaneous WILLIAM F. 2o 

